1. Technical Field
Embodiments of the present disclosure generally relate to internal voltage generation circuits, and semiconductor memory devices and systems including the same.
2. Related Art
In general, a semiconductor memory device receives an external voltage (e.g., a power supply voltage VDD) and a ground voltage VSS from an external device to generate internal voltages used in operation of internal circuits constituting the semiconductor memory device. The internal voltages for operating the internal circuits of the semiconductor memory device may include a core voltage VCORE, a high voltage VPP, and a back-bias voltage VBB. The core voltage may be supplied to a memory core region. The high voltage VPP may be used to drive or overdrive word lines. The back-bias voltage VBB may be applied to a bulk region (or a substrate) of NMOS transistors in the memory core region.
The core voltage VCORE may be a positive voltage which is lower than the power supply voltage VDD supplied by the external device. Thus, the core voltage VCORE may be generated by lowering the power supply voltage VDD to a certain level. However, the high voltage VPP may be higher than the power supply voltage VDD, and the back-bias voltage VBB may be a negative voltage which is lower than the ground voltage VSS. Thus, charge pump circuits may be required to generate the high voltage VPP and the back-bias voltage VBB.
In addition, the internal voltages used in the semiconductor memory device may include a bit line pre-charge voltage VBLP for pre-charging bit lines and a cell plate voltage VCP applied to a plate electrode of memory cells. The bit line pre-charge voltage VBLP and the cell plate voltage VCP may be set to have the same level (e.g., a half of the core voltage VCORE). Accordingly, the bit line pre-charge voltage VBLP and the cell plate voltage VCP may be generated by internal voltage generation circuits having the same configuration. The internal voltage generation circuits for generating the bit line pre-charge voltage VBLP and the cell plate voltage VCP may be realized to independently or separately operate.